(cos Ф -cos Ф)² + (cos Ф + cos Ф)²
Firstly: (cos Ф -cos Ф)² = 0² = 0
Secondly :(cos Ф + cos Ф)² = (2cos Ф)². = 4. (cos Ф)² = 4cos² Ф
Mind you when you raise a cosine (or sin or tan...) to the n power, the n power should affect the cosine only and NOT the angle Ф
Answer: -72a^3 +108a^2
Collect like terms
(2a)(6a)(2a-8a+9)= (2a)(6a)(-6a+9)=12a^2(-6a+9)
= -72a^3 +108a^2
Answer:
Step-by-step explanation:
Given that 33.4% of people have sleepwalked.
Sample size n =1459
Sample favourable persons = 526
Sample proportion p = 
Sample proportion p is normal for large samples with mean = 0.334 and
std error = 
a) P(526 or more of the 1459 adults have sleepwalked.)

b) Yes, because hardly 1.4% is the probability
c) 33.4 is very less compared to the average. Either sample should be improved representing the population or population mean should be increased accordingly.
Answer:
ummm what step?
whats the equation?
Step-by-step explanation: